The present invention relates to an intake air distributor for the cylinders of an internal combustion engine, in particular for motor vehicles, with the understanding that the term “air” must be considered in its broad sense and in particular to cover any gas intake mixture, in particular air/fuel mixtures.
In general, the intake air distribution in the cylinders of an internal combustion engine is carried out while attempting to eliminate or substantially reduce any imbalance in the feed to each of the cylinders, both for a given cylinder in case of a plurality of intake ducts and for the distribution between the cylinders. In diesel engines having two intake ducts per cylinder in particular, for which the aerodynamics of the intake gases is critical, drops in “swirl” have been observed in certain cylinders, in particular in the second distributed cylinder, caused by the geometry of the distributor (“swirl” can be defined as an axial eddy in the cylinder). This is true in particular of air distributors bent at 180°, particularly when, for reasons of size and compactness of the engines to be mounted in the engine compartment of a motor vehicle, the elbow is inclined to a diametral reference plane of the tubular body passing through the line of alignment of the branches of the connecting channels of the cylinder intake ducts.
The invention relates to a distributor for improved supply to the second distributed cylinder with regard to the geometry of the distributor and it is a particular object of the invention to remedy the drawbacks described above.
Publication JP2003074357 in particular teaches an air distributor for an internal combustion engine of the type having two intake valves per cylinder having an axial end air intake, and in which the curvatures of the connecting channels are suitable for making the “swirl” uniform between the cylinders. Publication JP63208616 also teaches an air distributor for an internal combustion engine having four cylinders in line, having one intake valve per cylinder, and a central lateral inlet between the second and third cylinders, and in which the inlet of the connecting channel of the third cylinder comprises an air guide to give the flow lines, upstream of the cylinder head, the same radius of curvature, and in the same direction, as at the second cylinder. Publication JP113509963 also teaches an air distributor without connecting channels for an internal combustion engine having three cylinders in line, of the type having one intake valve and in which projections are placed for adjusting to a constant profile between the first and second distributed cylinders and between the second and third distributed cylinders. It should be observed that the solutions proposed in these three Japanese publications for balancing the “swirl” between the cylinders only concern air distributors having particular structures and quite different from the bent air distributors, and for which the internal aerodynamic disturbances associated with or caused by these known distributors do not exist.